Lookup-table-based green imbalance correction system and method
a correction system and green imbalance technology, applied in the field of green imbalance, can solve the problems of green imbalance or mismatch, and the gain of green pixel in a line with red pixels usually differs from the gain of green pixel in the line,
Inactive Publication Date: 2014-12-25
HIMAX IMAGING LIMITED
View PDF2 Cites 1 Cited by
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Benefits of technology
The present invention provides a system and method for correcting green imbalance in an electronic apparatus. The system includes an image sensor and memory to store a lookup table. The system uses the lookup table to correct the raw data from the image sensor, resulting in corrected raw data. A color interpolation device is then used to receive the corrected raw data and produce full-color data. The system flexibly adapts to different assembled components of the electronic apparatus. Thermal imaging and infrared correction can also be provided.
Problems solved by technology
One of the disadvantages of the CMOS image sensor is that a gain of a green pixel (Gr) in a line with red pixels usually differs from a gain of a green pixel (Gb) in a line with blue pixels.
This gives rise to green imbalance or mismatch.
Some common causes of the green imbalance may be layout of photo diode, non-uniformity of a color filter array, lens coating and mounting, and mismatched amplifiers.
Therefore, overall green imbalance is ordinarily location dependent and non-uniform.
The green imbalance results in lines or cross hatched patterns that are annoying and cannot be negligible.
Conventional methods of overcoming the green imbalance are either computation intensive or incapable of adapting to an electronic apparatus with newly assembled components (e.g., lens).
Method used
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View moreImage
Smart Image Click on the blue labels to locate them in the text.
Smart ImageViewing Examples
Examples
Experimental program
Comparison scheme
Effect test
Embodiment Construction
[0014]FIG. 1 shows a block diagram illustrative of a lookup-table-based green imbalance correction system 100 according to one embodiment of the present invention. The system 100 of the embodiment includes an image sensor 11 (e.g., a complementary metal-oxide-semiconductor (CMOS) image sensor) with a color filter array (CFA) or color filter mosaic (CFM) 10, such as a Bayer CFA, placed over the image sensor 11, therefore outputting raw data. FIG. 2 shows a pattern of the Bayer CFA, which has 50% of green filters, 25% of blue filters and 25% of red filters. In other words, each two-by-two sub-array contains two green filters, one blue filter and one red filter. The color filters filter an incident light by wavelength range such that the outputted raw data give information about intensity of light in red, green and blue (RGB) wavelength regions.
[0015]Before the raw data are subjected to interpolation, by a color interpolation device 13, to result in full-color data that may, for exampl...
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More PUM
Login to View More Abstract
In a lookup-table-based green imbalance correction system and method, an image sensor with a color filter array placed thereover outputs raw data. A green imbalance correction device corrects the raw data according to a lookup table stored in a memory, thereby resulting in corrected raw data. A color interpolation device receives the corrected raw data to result in full-color data.
Description
BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]The disclosure generally relates to green imbalance, and more particularly to a lookup-table-based green imbalance correction system and method for an image sensor.[0003]2. Description of Related Art[0004]A Bayer color filter array (CFA) is commonly used in companion with an image sensor, such as a complementary metal-oxide-semiconductor (CMOS) image sensor, to capture color information. One of the disadvantages of the CMOS image sensor is that a gain of a green pixel (Gr) in a line with red pixels usually differs from a gain of a green pixel (Gb) in a line with blue pixels. This gives rise to green imbalance or mismatch. Some common causes of the green imbalance may be layout of photo diode, non-uniformity of a color filter array, lens coating and mounting, and mismatched amplifiers. Therefore, overall green imbalance is ordinarily location dependent and non-uniform. The green imbalance results in lines or cross hatche...
Claims
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More Application Information
Patent Timeline
Login to View More IPC IPC(8): G06T11/00
CPCG06T11/001G06T3/4015
Inventor SHIH, YEN-TE
Owner HIMAX IMAGING LIMITED